In a related art question answering apparatus, when hint information for obtaining an answer from an input question is insufficient in a process of obtaining the answer to the input question, a case incapable of obtaining an accurate answer occurs frequently. Therefore, in the related art question answering apparatus, a process of generating a question including the hint information is needed before a process of obtaining an answer to the question. For example, in a situation where a questioner is appreciating a specific work of art in a gallery, if the questioner desires to know a production year of the specific work of art, the questioner should a generate question sentence including a hint associated with an artist name or a title of the specific work of art to input the question sentence to the question answering apparatus. For example, if the questioner does not accurately know the artist name of the specific work of art or the time of the specific work of art, the questioner cannot generate an appropriate question sentence.
In order to solve such a problem, the related art question answering apparatus converses with a questioner through several turns, and thus, induces the questioner to generate an appropriate question. For example, if the questioner inputs a question including a short-length product name to the question answering apparatus, the question answering apparatus performs a process of checking with the questioner a name of a product which is highest in similarity to a name of a product, and the check process is repeatedly performed by performing conversation through several turns between the questioner and the question answering apparatus until searching for an accurate product.
As described above, in a question sentence input method performed by the related art question answering apparatus, even when a questioner does not know accurate information associated with a target to know, a question is finished through natural conversation between the questioner and the question answering apparatus.
However, such an interactive question sentence input method causes inconvenience due to conversation which is repeatedly performed through several turns between a questioner and the question answering apparatus.